Feb 18 (Reuters) - Three flight attendants and a number of passengers were injured after a United Airlines flight encountered severe turbulence as it approached a Montana airport, an airline spokesman said on Tuesday.

One passenger, Bill Dahlin, told Billings television station KTVQ there was a lot of screaming when the airplane dropped sharply during its descent on Monday, and a woman struck her head on the ceiling so hard a panel cracked.

The three flight attendants and two passengers were taken to a hospital after the incident on the flight to Billings, Montana, from Denver, Colorado, United said in a statement. One flight attendant remained hospitalized on Tuesday, United said.

“Our primary focus is assisting our employees and passengers who were injured, and our flight safety team will review what happened,” United said in its statement.

There were 114 passengers and five crew members aboard the airplane, a Boeing 737-700, which left Denver just before midday on Monday and landed in Billings at 1:23 p.m. local time, United said. (Reporting by David Bailey in Minneapolis; Editing by James Dalgleish)